實物一粒粒散掉
這一族是核心畫面的字面版本：真的有碎屑掉下來，看得見也摸得到。
crumble into bits · verb · C2
To fall into tiny bits, or to use your fingers to make food or another dry thing do the same.
弄碎
核心畫面
One way to picture it: something dry and solid coming apart into small loose bits — not snapped in half, but losing itself crumb by crumb, so that what held together is now a pile of pieces.
「整塊的東西一小粒一小粒地散掉」：不是被劈成兩半那種乾脆的斷裂，而是邊緣一直掉屑、一直掉屑，最後原本抱成一團的東西變…更多收起
「整塊的東西一小粒一小粒地散掉」：不是被劈成兩半那種乾脆的斷裂，而是邊緣一直掉屑、一直掉屑，最後原本抱成一團的東西變成一堆碎粒。關鍵有兩點——第一，材質是乾的、鬆的，所以才會掉屑而不是裂開；第二，它是漸進的，你看不到某一刻的「斷」，只看到它一路變少、變散。這個「逐漸粉碎、失去整體性」的畫面，就是這個字所有用法共同的底。From the word’s history
From Old English cruma 'crumb' plus the frequentative/diminutive -le: literally 'to keep making crumbs'. The bread-crumb picture sits directly inside the word.
這個字就是 crumb（麵包屑）加上表示反覆、細小動作的字尾 -le，字面意思是「一直掉屑、一直變成屑」。所以英文母語者聽到 crumble，腦中浮現的第一個材質其實是乾麵包：捏一下就一粒一粒落下來。知道這一點，後面石牆剝落、帝國瓦解的用法就都順了——它們都是在借那塊乾麵包的畫面。
Wiktionary (crumble), from Middle English kremelen / Old English *crymlan, related to Old English cruma 'crumb' + frequentative -le.
Three branches
抽象的東西垮掉
把那面剝落的石牆直接搬到抽象事物上：同樣是漸進的、由內而外的失去支撐，而不是一次性的斷裂。
crumble; collapse · verb · C2
When a country, an economy, a plan, or someone's courage grows weak and starts to fail.
瓦解
英式水果酥
名詞用法不是動詞意思的延伸，而是直接拿動作的產物來命名一道菜——重點從「散掉」轉成「那堆碎粒」。
crumble (fruit dessert) · noun · C2
Cooked fruit with a rough mix of flour, butter, and sugar baked over it, eaten as a sweet dish.
水果酥
原始詞典資料5 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
Crumblename
- 1
A surname.
crumbleverb/ˈkɹʌmbəl/
- 1
To fall apart; to disintegrate.
- The bread roll crumbled when I tried to slice it; it was too stale.
- The empire crumbled when the ruler's indiscretions came to light.
- 2
To break into crumbs.
- We crumbled some bread into the water.
- 3
To mix (ingredients such as flour and butter) in such a way as to form crumbs.
- Using your fingers, crumble the ingredients with the fingertips, lifting in an upward motion, until the mixture is sandy and resembles large breadcrumbs.
crumblenoun/ˈkɹʌmbəl/
- 1
A dessert of British origin containing stewed fruit topped with a crumbly mixture of fat, flour, and sugar.
- blackberry and apple crumble
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。